Dermatologist can devise 'sun allergy' treatment plan

Dr. Douma

Posted: Tuesday, July 31, 2001

DEAR DR. DOUMA: I'm a 37-year-old woman and was recently diagnosed with solar urticaria. I can't be in the sun for more than a few minutes or I'll break out in a severe rash and itch uncontrollably. Would you explain why this occurs for no apparent reason and what treatment would be best? -- D.I., Missouri

ANSWER: Urticaria can be a frustrating condition. It must be especially frustrating to be ''allergic'' to the sun. I wish I could offer you a quick fix, but I don't know of one.

Urticaria in general is characterized by itchy, sometimes weeping, red swellings (wheals or hives) of various sizes on the skin. It is usually a short-term allergic or immune reaction to external chemicals.

It also may be part of an abnormal immune response of the body against itself. Physical factors such as heat, cold, sunlight, injury and pressure can also cause hives on occasion, as you have found out.

Ordinarily, the cause of acute or short-term urticaria is often easy to pinpoint, e.g., allergy to strawberries. This form of urticaria usually goes away by itself once the cause is removed. That's easier said than done when the cause is sensitivity (but not allergy) to sunlight.

Chronic urticaria, usually defined as having episodes lasting more than six weeks, is quite another matter. Half of those whose episodes of urticaria last that long will have the condition recurring for years.

Solar urticaria is an uncommon acute photosensitive condition characterized by redness, itching and hives, similar to non-photosensitive urticaria. The condition occurs after exposure to an ultraviolet light source such as sunlight.

The exact relationship between ultraviolet light and solar urticaria is not known. Similar photosensitive conditions include phototoxic reaction, photoallergic reaction, lupus and porphyria.

One study of a group of solar urticaria patients found that it generally affects both sexes, usually under 30 years of age, and that half the people with this condition are free of it within five years. Many of these patients had histories of other urticaria.

Lesions tend to appear within 30 minutes of sun exposure and disappear within 24 hours.

Diagnosis is confirmed by phototesting, where an ultraviolet light source is shown on an area of skin to elicit the urticarial response.

It certainly sounds like the diagnosis of solar urticaria is correct, but I hope a dermatologist performed this test on you. As I noted above, there are a number of photosensitive conditions similar to solar urticaria and care and treatment may be different for each.

Antihistamines are useful first-line therapy for solar as well as other urticaria. Severely affected people may require phototherapy with psoralens and ultraviolet light (PUVA).

After confirming this diagnosis, I suggest you work with a dermatologist to arrive at a plan for treatment and, even better, prevention. You may want to find out if other factors, e.g., prescription drugs, are contributing to your sensitivity.

UPDATE ON BACK PAIN: Chronic back pain is one of the most common conditions people experience. It is not only painful, but it can damage a person's ability to work and simply enjoy daily life.

Unfortunately, chronic back pain can also be one of the most frustrating medical conditions to bring under control. So recent research indicating that a new treatment shows promise can be great news for millions of people with the problem, as well as their health practitioners.

The research showed that one of the most deadly poisons known to man -- botulinum toxin -- relieved muscle spasm, decreased pain and improved functioning in almost three-fourths of those treated. And no negative side effects were seen in the small group tested. However, it appears that the positive effects may wear off after about three months.

Further research on many more people needs to be done to confirm the benefits and risks. But if the preliminary results hold up, it will be great news for millions of people.

This article published in the Athens Banner-Herald on Tuesday, July 31, 2001.